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Abstract:

A storage module for flat articles, has a storage region for a stack of
articles, an introduction unit for the introduction of articles from an
article stream into the storage region, and a draw-off unit arranged at
the same end of the stack as the introduction unit, for drawing off
articles from the storage region. The storage module has a movement
device for moving the stack away from the introduction unit toward the
draw-off unit. The storage module thus provides for an intermediate
storage of the articles, which is protective of the mail items.

Claims:

1-16. (canceled)

17. A storage module for flat articles, comprising: a storage region for
a stack of flat articles; an introduction unit for introducing articles
from an article stream into said stack; a draw-off unit, arranged at a
same end of the stack as said introduction unit, for drawing off articles
from said storage region; a movement device for moving at least a part of
the stack which includes an article deposited last in said stack away
from said introduction unit toward said draw-off unit; and a stop having
a stop position for stopping an introduction of the articles, and a
movement element for moving said stop out of the stop position into a
release position.

18. The storage module according to claim 17, including a stack carrier
for holding the stack of articles, and a drive device for moving said
stack carrier between said introduction unit and said draw-off unit.

19. The storage module according to claim 17, including a stack carrier
for holding the stack of articles, a carrying device for carrying said
stack carrier, said movement device constructed to move at least part of
the stack in relation to said carrying device away from said introduction
unit and toward said draw-off unit.

20. The storage module according to claim 17, wherein said movement
device moves at least a part of the stack in a direction substantially
parallel to a flat side of the stacked articles.

21. The storage module according to claim 17, wherein said movement
device moves at least a part of the stack in a longitudinal direction of
the stacked articles.

22. The storage module according to claim 17, wherein said movement
device moves at least a part of the stack in a straight translational
direction of the overall stack.

23. The storage module according to claim 17, wherein said movement
device moves at least a part of the stack in a pivotal direction of the
stack.

24. The storage module according to claim 23, wherein a stack carrier for
holding the stack is arranged on both sides of a pivot axis of the
pivotal direction.

25. The storage module according to claim 17, wherein said stop is
coupled by force to a movement of the stack.

26. The storage module according to claim 17, including a process device
for controlling a speed of the movement that it is equal to a speed of
introduction of articles into said storage region.

27. The storage module according to claim 17, including a process device
for controlling a speed of the movement such that an article introduced
last into said storage region is drawn off and transported further
without an interruption in the introduction movement.

28. The storage module according to claim 17, including a stack carrier
for holding the stack of articles, and a pushing device which bears
against a trailing edge of articles stacked in said storage region and
pushes the articles in the direction of movement.

29. The storage module according to claim 28, wherein said pushing device
has a plurality of edges arranged one behind the other in a stair-like
configuration in a longitudinal direction of the articles.

30. The storage module according to claim 28, wherein said pushing device
has a brush element which bears against the trailing edges.

31. The storage module according to claim 17, wherein said draw-off unit
includes a draw-off element to draw on an article to be drawn off, and
said introduction unit has an introduction element to push an article
into said storage region, said draw-off element has a higher coefficient
of friction than that of said introduction element

Description:

[0001] The invention relates to a storage module for flat articles, with a
storage region for a stack of articles, with an introduction means for
the introduction of articles from an article stream into the storage
region, and with a draw-off means, arranged at the same end of the stack
as the introduction means, for drawing off articles from the storage
region.

[0002] Flat articles, such as letters, large letters, postcards, sealed-up
periodicals and the like, are sorted in very large numbers according to
their address in postal centers or large post offices and, if appropriate
after being presorted, are filed in a multiplicity of stacking
compartments. To sort the articles according to their address, it is
indispensible to detect the address of as far as possible each article
mechanically at least at the start of the sorting process.

[0003] Depending on how the address is applied to the article, the address
can be detected mechanically more or less easily, although the address of
some of the articles to be sorted usually cannot be detected
mechanically. It has to be fed into the system by means of a manual
input. For this purpose, an image of the article having the undetected
address is brought up on a video display unit, the address is read by an
operator and input via the keyboard. Such an operation takes up some
time. This situation makes it necessary for the further processing of the
articles having the mechanically unreadable addresses to be delayed until
their address is known to the system.

[0004] For this purpose, storage zones are known, in which, for example,
all the articles are transported to and fro as long as there is
sufficient time available for the manual identification of the non-read
addresses. Another solution to this problem provides for the mechanically
unreadable mail items to be transferred out of the sorting process and
intermediately stored in a storage module. After the manual assignment of
the address, the articles are drawn off from the storage module again and
introduced into the sorting process.

[0005] A storage module for the reception of articles which are to be
intermediately stored is known, for example, from EP 1 872 865 A2. The
storage module operates in the last-in/first-out mode in which the
article stored last is drawn off first and separated. It comprises an
introduction means in the form of two endless belts which lie opposite
one another and between which the articles are delivered to a storage
region for the reception of stacked articles. For stacking the articles
into the storage region, moreover, the introduction means comprises a
roller conveyor unit which draws in a transported article, rotates it a
little and places it on the stack. To draw off the stacked articles,
these are pressed onto the roller conveyor unit, a feed stop is opened,
and the articles are drawn off successively by the roller conveyor unit
and separated.

[0006] An object of the present invention is to specify a storage module
for flat articles, by means of which an introduction and draw-off of the
articles can be carried out particularly carefully with regard to the
consignments involved.

[0007] This object is achieved by means of a storage module of the type
initially mentioned which, according to the invention, has a movement
means for moving at least such a part of the stack which comprises an
article last deposited in the storage region away from the introduction
means and toward the draw-off means. The introduction means and the
draw-off means may operate as separate units, for example without a
roller conveyor unit being used either for stacking or for drawing off.
As a result, introduction which is careful with regard to the
consignments involved and which has low static friction can be carried
out, and draw-off can take place with high static friction for the rapid
and reliable acceleration of the articles.

[0008] The invention is in this case based on the consideration that
articles to be stacked are shot in onto the end of the stack and butt
against a stop for stopping an introduction movement, with the result
that a uniform stack formation can be achieved. The movement of the
articles is in this case pursued as far as the stop at the introduction
means, so that the latter also comes into contact with the article when
the articles are stopped at the stop. Since a relative speed between the
supported articles and the supporting element cannot be avoided, support
should take place with a very low coefficient of friction, in order to
avoid a creasing of the articles.

[0009] When the articles are being drawn off from the stack, they are
accelerated sharply. To achieve the high acceleration, the draw-off means
must engage with high friction on the article to be drawn off in each
case. The draw-off means therefore expediently has high static friction
with respect to the articles. Since the introduction means is intended
for introducing the articles independently into the storage region and
the draw-off means is present as an additional component to the
introduction means, that is to say due to the separation of the
introduction means and draw-off means, the articles, when being stored
and when drawn off, are treated with means completely separate from one
another, so that the friction occurring between the means and the
articles can be optimized in terms of the process to be carried out in
each case.

[0010] The storage module is expediently a last-in/first-out module in
which the article stored last is drawn off first. The flat articles may
be mail items of any type, in particular postal consignments, the
thickness of which preferably does not overshoot 20% of their height. The
height relates to an article which is standing on a longitudinal edge.
The draw-off means expediently has a draw-off element for drawing on an
article to be drawn off, said element applying a force in the draw-off
direction to the articles, that is to say drawing these off. The
introduction means serves for the introduction of articles from an
article stream into the storage region.

[0011] An article stream comprises a plurality of articles transported one
behind the other and in each case standing on their longitudinal edge. It
may comprise an introduction element for pushing an article into the
storage region, the draw-off element having a higher coefficient of
friction than the introduction element. The coefficient of friction may
be seen in relation to paper. The introduction element may be a revolving
endless belt, and the draw-off element likewise, or the latter may be
formed by one or more rollers. The movement of the stack or a part of the
stack away from the introduction means and toward the draw-off means may
be designated as a changeover movement for changing over the storage
module from an introduction operating mode to a draw-off operating mode,
even though it is generally designated below merely as the movement.

[0012] In an advantageous refinement of the invention, the storage module
comprises a drive for moving a stack carrier for holding the stack of
articles from the introduction means to the draw-off means. The movement
of the stack in relation to the introduction means and to the draw-off
means can thereby take place in a mechanically driven manner, with high
power, swiftly and reliably.

[0013] The relative movement of the part of the stack in relation to the
introduction means and to the draw-off means may be such that the storage
region or a stack carrier for holding a stack of articles which is stored
in the storage region is stationary, that is to say remains
unaccelerated, and the introduction means and the draw-off means are
accelerated for carrying out the relative movement.

[0014] A simpler incorporation of the introduction means and of the
draw-off means into a transport train can be achieved if the stack or the
stack carrier are accelerated during the movement and the introduction
means and the draw-off means are stationary or can execute other
movements. The movement of the stack or stack carrier then takes place in
relation to a carrying device for carrying the stack carrier, for example
a stand or a substructure. It is likewise conceivable to accelerate both
the stack and the introduction means and draw-off means, expediently
contradirectionally, so that an acceleration can have less effect on the
stack.

[0015] The movement of at least part of the stack expediently takes place
parallel to a flat side of the stacked articles. This movement may be
perpendicular to the stacking direction of the stack. As a result, the
stack or its article last stored can be moved away from the introduction
means and toward the draw-off means particularly reliably and
unsusceptibly to faults, without many elements having to be moved.

[0016] The movement advantageously takes place in the longitudinal
direction of the stacked articles, that is to say expediently in an
introduction direction in which the articles are moved onto a stop. An
uninterrupted further transport of the article last introduced into the
storage region can thereby be achieved.

[0017] The movement means for moving at least part of the stack can be
kept particularly simple if the movement is a straight translational
movement of the overall stack.

[0018] If the movement is a pivoting movement of the stack, then
acceleration forces on the stack can be kept low. Since an at least
substantial translational movement of the article last stacked along the
introduction means and the draw-off means is particularly beneficial, a
pivot axis of the pivoting movement preferably lies such that the article
last stacked of all the stacked articles is furthest away from the pivot
axis.

[0019] When the stack is accelerated to carry out the movement, the stack
should as far as possible not be moved in relation to a stack carrier for
holding the stack, that is to say it should not or should as little as
possible slip on the latter. This can be carried out the more easily, the
lower the acceleration on the stack is. The stack is particularly
unstable in its middle region. The acceleration on the stack can be kept
low, particularly in the middle region, if the stack carrier is arranged
on both sides of a pivot axis of the pivoting movement. The overall stack
can be pivoted about the pivot axis in the manner of two propeller blades
lying opposite one another, and the middle region can remain at least
essentially stationary. For this purpose, the pivot axis is expediently
led through the storage region, in particular through the center of
gravity of a stack of maximum length.

[0020] In a further embodiment of the invention, the storage module
comprises a stop with a stop position for stopping an introduction
movement of the articles and a movement element for moving the stop out
of the stop position into a release position. The articles, when being
drawn off, can be led past the stop in a particularly simple way.

[0021] A movement of the stop is expediently coupled positively to the
movement of the stack. As a result, the stop can be drawn back, for
example automatically, when the stack is moved and thereby be changed
over from an introduction function to a draw-off function. The movement
of the stop is expediently in relation to the stack carrier.

[0022] It is proposed, moreover, that the storage module advantageously
comprise a process means for controlling a speed of the movement, in
particular such that the speed is equal to a speed of introduction of
articles into the storage region. The stack can be moved even while the
last article is being shot into the stack, without a relative speed
between the moved stack and the last articles occurring at any time
point. A particularly swift changeover between the stacking function and
the draw-off function can be achieved.

[0023] The process means for controlling a speed of the movement is
expediently provided in such a way that an article introduced last into
the storage region is drawn off and transported further on without an
interruption in the introduction movement. A changeover from an
introduction function to a draw-off function can therefore take place
without an interruption or with only a minor interruption in an article
stream on the storage module.

[0024] During the movement of the stack, it is advantageous if the latter
is supported in the direction of movement, so that a break-up of the
stack is prevented. For this purpose, the storage module advantageously
comprises a stack carrier for holding the stack of articles, with a
pushing means for bearing against a trailing edge of articles stacked in
the storage region and for pushing the articles in the direction of
movement. With front and rear having to be seen in relation to the
introduction direction, so that, when an article is being introduced, the
trailing edge is the rear edge, the stack can be supported by the
trailing edges, and therefore a slipping of the stack out of place on the
stack carrier is counteracted.

[0025] The pushing means advantageously comprises a plurality of edges
which are arranged one behind the other in a stair-like manner in the
longitudinal direction of the articles. The trailing edge of an article
can be supported by an edge, and the article can thereby be pushed in the
direction of movement by the edge, with the result that a movement of the
article in relation to the stack carrier can be at least substantially
avoided. Articles of different length can be supported by the plurality
of edges arranged one behind the other.

[0026] In a further advantageous refinement of the pushing means, the
pushing means has a brush element for bearing against the trailing edges.
The brush, when being pressed onto the stack, adapts itself automatically
to the stack shape and thereby supports the stack. The brush element is
expediently laid against the stack, that is to say moved toward it,
before the start of the movement of the latter, so that the brush does
not previously disturb a stacking movement of the stack in the stacking
direction. For this purpose, the stack carrier expediently comprises a
movement means for moving the brush element toward the stack, the
movement expediently being a pivoting movement and, in particular, being
coupled positively to the movement of the stack.

[0027] The invention relates, moreover, to the use of a storage module, as
described above, for the storage of flat articles.

[0028] The invention is explained in more detail by means of exemplary
embodiments illustrated in the drawings in which:

[0029]FIG. 1 shows a top view of a storage module with an introduction
means and with a draw-off means in an introduction operating mode,

[0031]FIG. 3 shows a storage module which can be moved vertically from an
introduction operating mode into a draw-off operating mode,

[0032]FIG. 4 shows a storage module which can be moved from an
introduction operating mode into a draw-off operating mode by means of a
pivoting movement, and

[0033]FIG. 5 shows a storage module which can be moved from an
introduction operating mode into a draw-off operating mode by means of
another pivoting movement.

[0034]FIG. 1 shows a diagrammatic top view of a storage module 2 with an
introduction means 4 and a draw-off means 6 and with a stack 10 of
stacked articles 12 which is arranged in a storage region 8. The articles
12 are postal consignments which in the storage module 2 stand on their
lower longitudinal edge on a stack carrier 14 of the storage module 2. It
is also conceivable, however, to store the articles 12 lying flat in the
storage module 2.

[0035] The introduction means 4 and the draw-off means 6 are arranged at
the same end of the stack 10. The storage module 2 is shown in FIG. 1 in
an introduction mode in which the stack 10 is arranged on the
introduction means 4. Articles 12 from an article stream 16 are
transported by endless belts 18, 20 of the introduction means 4 in the
direction of the stack 10 and are shot in at a high speed of, for
example, above 4 m/s between the belt 18 and the end of the stack 10, so
that the article 12 last introduced butts against a stop 22 and is
stopped there.

[0036] For the frictionless stacking of the articles 12 from the article
stream 16 into the storage region 8, the articles 12 previously spaced
apart from one another in the article stream 16 are pushed together into
an imbricated stream, as indicated in FIG. 1, so that the articles 12
reach the stack 10 with a slight overlap. A supporting means 24, designed
as a paddle, at the other end of the stack 10 prevents a tilting of the
articles 12 in the stack 10 and can be moved in translation in the
stacking direction 28, for example, along a rail element 26 or in another
way. The movement of the supporting means 24 is controlled by a process
means 30 which is connected to a sensor, not illustrated, for measuring
the stack pressure in the stack 10. If the stack pressure overshoots a
predetermined value, the supporting means 24 is moved a little way to the
rear in the stacking direction 28.

[0037] When stacking comes to an end, for example because the article
stream 16 has ceased, and the articles 12 of the stack 10 are to be
separated into a new article stream, the storage module 2 changes from
the introduction operating mode to the draw-off operating mode which is
illustrated in FIG. 2. For this purpose, the stack 10 must be moved to
the draw-off means 6, in order to come into frictional force-generating
contact with the belt 32 of the latter for drawing off the articles 12.
For this purpose, the stack carrier 14 can be moved in translation in a
direction of movement 36, for example, by means of a rail system 34. The
direction of movement 36 is in this case oriented parallel to a flat side
of the stacked articles 12 and, in particular, parallel to their
longitudinal edge, in its longitudinal direction, with which the articles
12 stand on the stack carrier 14.

[0038] For carrying out the movement in the direction of movement 36, the
storage module 2 comprises a movement means 38 with electric drives 40
which, controlled by the process means 30, transmit a force to toothed
belts 42 which draw the stack carrier 14 to or fro in the direction of
movement 36. A drive 40 without toothed belts 42 and an alternative means
for the transmission of force for moving the stack carrier 14 may also be
envisaged.

[0039]FIG. 2 shows the storage module 2 in a draw-off operating mode with
the stack carrier 14 in a draw-off position. As compared with the
introduction operating mode from FIG. 1, the stack carrier 14 is
displaced in the direction of movement 36 by somewhat more than 10 cm in
relation to a carrying device 44 which carries the stack carrier 14 and,
for example, stands on a floor. During this movement the stop 22 has been
moved by a movement element 46 from its stop position, shown in FIG. 1,
into a release position, shown in FIG. 2, the movement of the stop 22
being coupled positively to the movement of the stack carrier 14.

[0040] During a movement of the belt 32 of the draw-off means 6, then, the
article 12 last stacked, which then bears against the belt 32, is drawn
by the belt 32 in a draw-off direction 48 which is parallel to an
introduction direction 50 of the introduction means 4. To assist the
force transmitted from the belt 32 to the article 12 as a result of
friction, the draw-off means 6 comprises a suction unit 52 for generating
a vacuum which can penetrate through recesses in the belt 32 or between
the belts 32 as far as the article 12 to be drawn off. As a result of
frictional action, the article 12 to be drawn off is accelerated to a
draw-off speed, which is controlled by the process means 30, and is
transferred to a transport system 54 for the further transport of the
articles 12 then arranged in an article stream.

[0041] In order at least as far as possible to avoid double draw-offs, the
draw-off means 6 comprises a stripper 56 for stripping off one or more
further articles 12 lying on an article 12 to be drawn off. To assist the
frictional action of the belt 32 on the article 12 to be drawn off, the
belt 32 is provided with a soft covering having a high coefficient of
friction on paper which is substantially higher than that of a covering
of the belt 18 of the introduction means 4.

[0042] A relative speed between a moved article 12 and the belt 18
therefore entails only an insignificant mechanical load on the article
12.

[0043] To maintain an article stream 16, the process means 30 is prepared
in such a way that it controls the movement of the stack carrier 14 in
the direction of movement 36 away from the introduction means and toward
the draw-off means 6 at an introduction speed at which the articles 12 in
the article stream 16 are introduced into the stack 10. The movement of
the stack carrier 14 may in this case be controlled such that the stack
carrier 14 is being accelerated in the direction of movement toward the
draw-off means 6 even when the article 12 last stacked has not yet
reached the stop 22. This article 12 is therefore not braked or hardly
braked, whereas the stack 10 is accelerated to the speed of this article
12. The article 12 last stacked reaches the draw-off means 6 and is
sucked by the suction unit 52 onto the belt 32, picked up by the latter
and transported further on to the transport system 54 at the draw-off
speed, which may be equal to the introduction speed, without an
interruption in the introduction movement.

[0044] On account of the high acceleration of the stack carrier 14 in the
direction of movement 36 toward the draw-off means 6, it is necessary to
transmit a high force to the stack 10 for its acceleration. Owing to the
inertia of the stack 10, it may happen that it lags behind in its
movement and slips out of place on the stack carrier 14. A long stack 10
may in this case bend in a middle region, so that the stack 10 becomes
disorganized and can no longer be drawn off.

[0045] In order to avoid this, the storage module 2 comprises on the stack
carrier 14 a pushing means 58 for pushing the stack 10 in the direction
of movement 36 toward the draw-off means 6 at or shortly after the start
of a slipping out of place of the stack 10 on the stack carrier 14. The
pushing means 58, shown from above in FIG. 1, comprises a number of edges
60 which ascend in a stair-like manner from left to right, that is to say
opposite to the introduction direction 50. The articles 12 of the stack
10 are thereby, on the one hand, held at their leading edge against a
stop 62 of the stack carrier 14 and, on the other hand, held with their
trailing edge 64 at the next edge 60 which is arranged behind the
trailing edge 64 and against which the trailing edge 64 of the articles
12 butts when they slip onto the stack carrier 14. A considerable
slipping of the stack 10 out of place and, in particular, a break-up of
the stack 10 are thereby reliably avoided.

[0046] To illustrate another exemplary embodiment, the pushing means 58 is
provided in FIG. 2, instead of with the edges 60, with a brush element 66
which comprises a brush fastened to a carrier 68. The brush engages
between the articles 12, as is illustrated diagrammatically by the
meandering line of the brush element 66 in FIG. 2, and presses the
articles 12 at their trailing edges 64 toward the stop 62. So as not to
obstruct a stacking and an associated movement of the stack 10 in a
stacking direction 28, the brush element 66 may be moved, for example by
being swung in, against the trailing edges 64 of the stack 10 only after
or shortly before the conclusion of the introduction operating mode.

[0047]FIG. 3 shows an alternative storage module 70 in a diagrammatic
side illustration. The following description is restricted essentially to
the differences from the exemplary embodiment in FIGS. 1 and 2 to which
reference is made in respect of features and functions which remain the
same. Components essentially remaining the same are basically designated
by the same reference symbols.

[0048] The storage module 70 has essentially the same set-up as the
storage module 2, but comprises an alternative movement means 72 for
moving the stack carrier 14 in a vertical direction of movement 74. The
draw-off means 6 is in this case arranged vertically above the
introduction means 4, so that the stack 10, when moved from the
introduction means 4 to the draw-off means 6, is guided upward. As a
result, a good hold of the stack 10 on the stack carrier 14 can be
achieved, and an unwanted break-up of the stack 10 does not occur. For
clarity, the stack 10 and the stack carrier 14 are illustrated by
unbroken lines in the introduction operating mode and by dashes in the
draw-off operating mode at the draw-off means 6.

[0049] It is also conceivable, of course, to arrange the introduction
means 4 above the draw-off means 6. This is advantageous particularly
when a translational direction of movement 74 is not selected, but,
instead, a rotational direction of movement 76 about a pivot axis 78 or
pivot axis 80. However, the speed of movement of the stack 10 should in
this case not overshoot a falling speed, in order to prevent the stack 10
from being lifted off from the stack carrier 14. Thus, in this
configuration, stacking in an upper position of the stack can take place
by the stack 10 being pressed somewhat away from the introduction means 4
as a result of gravity. Conversely, in the draw-off operating mode in the
lower position, the stack 10 is pressed somewhat onto the draw-off means
6 as a result of gravity. Depending on the direction of movement 74, 76
either by translation or about the pivot axis 78 or 80, more, less or
even less energy is necessary for accelerating the stack 10. In a
movement about the pivot axis 80, the stack carrier 14 for holding the
stack 12 is arranged on both sides of the pivot axis 80.

[0050] A movement of the stack 10 or stack carrier 14 about a pivot axis
82 outside the stack 10 or about a pivot axis 84 inside the stack 10 may
likewise be envisaged, as illustrated in FIGS. 4 and 5. In this case, the
stack 10 or its article 12 last placed onto the stack is likewise moved
in a rotational direction of movement 86, 88. This, too, makes it
possible to counteract a break-up of the stack 10, since, above all in
the exemplary embodiment from FIG. 5, only low forces act on the middle
region of the stack 10. However, as described with regard to FIG. 1 or
FIG. 2, the outer regions must advantageously be supported in order to
stabilize the stack 10 on the stack carrier 14. In a similar way to FIG.
3, in FIGS. 4 and 5 the stack 10 and the stack carrier 14 are illustrated
by dashes in the draw-off operating mode of the draw-off means 6.

[0051] In a further design variant, a relative movement of the stack
carrier 14 in relation to the introduction means 4 and to the draw-off
means 6 may be envisaged, in such a way that the stack carrier 14 is
stationary on the carrying device 44 and the introduction means 4 and
draw-off means 6 are accelerated for the change from the introduction
operating mode to the draw-off operating mode or back and move in
relation to the carrying device 44. The stack 10 can in this case remain
stationary and is thereby optimally stable. However, it is necessary to
adapt the introduction means 4 or draw-off means 6 to the delivering or
discharging transport system 54, for example by the length of the latter
being variable under the control of the process means 30.

Patent applications by Peter Enenkel, Konstanz DE

Patent applications by SIEMENS AKTIEGESELLSCHAFT

Patent applications in class Including separate unstacking means

Patent applications in all subclasses Including separate unstacking means